Obama's tax returns: Income drops

President Obama's income declined last year due to slower sales of his books, according to tax returns released Friday.

President Obama and the first family saw their income drop slightly in 2012, according to tax returns released by the White House on Friday.

The returns show the president and First Lady Michelle Obama earned $608,611 last year, and paid $112,214 in taxes. Sales from his best-selling books slowed even further in 2012, bringing his overall gross adjusted income down 30% compared to 2011.

Obama's effective tax rate in 2012 was about 18.4%. He overpaid taxes last year to the tune of $16,815, according to the return. But instead of a refund, the president chose to apply the overpayment to his 2013 tax bill.

The president earns a salary of $400,000 for his day job. His total earnings are higher because his books -- "Dreams From My Father," and "The Audacity of Hope" -- continue to attract buyers.

The Obamas donated $150,000, or 24% of their income, to 33 different charities.

Obama is donating the proceeds from his latest book, "Of Thee I Sing," to a Fisher House scholarship fund for children of fallen and disabled soldiers. In 2012, the contribution was $103,871.